This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The general aim of the project is to determine the processes that characterize behavior and brain activation of individuals when they are comparing their performance and that of other subjects in the same task. The subjects in the experiment will also have the possibility of reducing the payment to other subjects if they choose to do so. This and the stated affective state will rpovide the behavioral correlates of the brain data. We are particularly interested in the interaction between cortical areas involved in the cognitive side of the comparison, and areas (like the basal ganglia) that are specifically devoted to the evaluation of rewards. Laboratory and imaging experiments that we have conducted previously have determined that subjects who have the choice are willing to pay to reduce the score of other subjects. The hypothesis is that the process induced by this choice involves a combination of affective and cognitive brain centers